Fused pyrrolo[2,3-c]carbazole-6-ones

ABSTRACT

Disclosed in this patent document are synthetic, biologically active molecules referred to as fused pyrrolo[2,3-c]carbazole-6-ones. These molecules are represented by the following general formulae: ##STR1## Methods for making and using the fused pyrrolo[2,3-c]carbazole-6-ones are also disclosed.

FIELD OF INVENTION

This invention is related to pharmaceutical compounds which are referredto in this patent document as "fused pyrrolo[2,3-c]carbazole-6-ones".Also disclosed are methods for making these compounds, and methods forusing the compounds.

BACKGROUND OF THE INVENTION

Human interferon-gamma (IFN-γ) is a natural human immunoregulatoryprotein. It has been established as an agent effective in the treatmentof tumors and virus infections in humans. The precise mechanisms bywhich IFN-γ inhibits virus and tumor growth in vivo remain unknown.There is evidence that IFN-γ works by at least one of two mechanisms:(1) by acting directly on the virus infected cell and the tumor celland/or (2) by first activating cells of the immune system which thendestroy the virus-infected cell or tumor cell [Interferons and otherRegulatory Cytokines, E. De Maeyer and J. De Maeyer-Guignard, John Wiley& Sons, New York (1988)].

One manifestation of a stimulated immune system is the enhancedexpression on the surface of immune cells of the proteins of the MajorHistocompability Complex (MHC). The MHC is made of class I, II, and IIIgenes that code for the respective class I, II, and III proteins. ClassI and II proteins reside on the cell surface and are involved incontrolling the immune response, whereas the class III proteins appearin the serum and are not involved in controlling the immune response.Class I and II proteins on antigen presenting cells e.g. monocytes, Blymphocytes, dendritic cells, present foreign antigens to T lymphocyteswith subsequent destruction of the cell containing the foreign antigen.The enhanced expression of the class I and II proteins is essential forthe immune system to rid an animal of virus-infected cells and enhancespecific antibody production. IFN-γ is one of the major regulators ofthe immune response due to its ability to enhance the expression of MHCclass I and II proteins. An example of the benefit of MHC I enhancementby IFN-γ is the enhancement of class I proteins on virus-infected cells.The virus infected cell presents synthesized viral antigens on its cellsurface to the T cell receptor on cytotoxic T cells (CD4 cells) with thesubsequent destruction of the virus infected cell by the cytotoxic Tcell. An example of the benefit of MHC II enhancement by IFN-γ is theenhancement of class II proteins on monocytes. Monocytes can ingestinvading microorganisms and the class II proteins on the monocytesurface present peptides derived from the invading microorganism. Thesepeptides held by the class II proteins are presented to the T cellreceptor on helper T cells (CD8) with subsequent secretion oflymphokines by the CD8 cell. The secreted lymphokines causeproliferation of the antibody synthesizing B lymphocytes whichsynthesize large amounts of antibody against the invading microorganism.

It can be seem from the above examples that a compound that enhances theIFN-γ induction of MHC molecules would be useful in combination withIFN-γ for the treatment of infections by microorganisms. Such a compoundmight permit a reduction in the dose of IFN-γ, thereby advantageouslygiving the same therapeutic effect as with IFN-γ alone but with fewer ofthe IFN-γ related side effects.

There are at least three reports of compounds that potentiate theIFN-γ-induced MHC expression [Coutinho, G. C., Dudrieu-Trautmann, O.,Strosberg, A. D., and Couraud, P. O., Catecholamines Stimulate theIFN-γ-induced Class II MHC Expression on Bovine Brain CapillaryEndothelial Cells, J. Immunol., 147, 2525-2529 (1991); Zhu, J., Mix, E.,Olsson, T., and Link, H., "Influence of Ion Channel Modulation of inVitro Interferon-γ Induced MHC Class I and II Expression onMacrophages", Immunopharmacology and Immunotoxicology, 17, 109-136(1995); Mothes, T., Bendix, U.,, Pfannschmidt, C.,, and Lehmann, I.,"Effect of Gliadin and Other Food Peptides on Expression of MHC Class IIMolecules by HT-29 Cells", Gut, 36, 548-552 (1995)].

SUMMARY OF THE INVENTION

Disclosed herein are a novel class of molecules represented by FormulaeI and II, which we refer to as fused pyrrolo[2,3-c]carbazole-6-ones.##STR2## Constituent numbers are defined, infra. Preferred methods forpreparing these compounds are disclosed infra.

We have discovered that our fused pyrrolo[2,3-c]carbazole-6-onecompounds (numbering as designated for K-252a and K-252c set forth inMoody et. al, J. Org. Chem., 1992, 57, 2105) potentiate the activity ofhuman IFN-γ in inducing the expression of MHC on the surface ofreceptive cells. The compounds of the invention show ability forenhancing the effectiveness of the immune system, and this in turnprovides, beneficially, an enhancement in inhibiting virus and/or tumorgrowth. We have also discovered that the fusedpyrrolo[2,3-c]carbazole-6-one compounds of the invention are useful forpotentiating, preferably, neurotrophin-3 (NT-3) activity.

DETAILED DESCRIPTION

We first describe the drawings.

I. BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing the enhancement of IFN-γ-induced expression ofHLA-DR MHC II molecule by pyrrolo[2,3-c]-carbazole-6-ones of theinvention.

FIG. 2 is a schematic drawing outlining the chemical synthesis of thepyrrolo[2,3-c]-carbazole-6-ones of Formula I, Section V (A)-(D).

FIG. 3 is a schematic drawing showing the synthesis of intermediates topyrrolo[2,3-c]-carbazole-6-ones.

FIG. 4 is a schematic drawing showing an alternate synthesis ofintermediates to pyrrolo[2,3-c]carbazole-6-ones.

FIG. 5 is a schematic drawing showing the synthesis ofpyrrolo[2,3-c]carbazole-6-ones of Formula II.

FIG. 6 is a schematic drawing showing the synthesis ofpyrrolo[2,3-c]carbazole-6-ones in which X is C═O from the correspondingcompounds in which X is CH₂.

FIG. 7 is a schematic drawing showing the synthesis of intermediate 11to pyrrolo[2,3-c]carbazole-6-ones.

II. Fused pyrrolo[2,3-c]carbazole-6-ones

The novel compounds of this invention, which are referred to as fusedpyrrolo[2,3-c]carbazole-6-one derivatives are represented by thefollowing Formulae: ##STR3## wherein:

a) R¹ is selected from the group consisting of H, alkyl of 1-4 carbons,aryl, arylalkyl, heteroaryl, heteroarylalkyl; C(═O)R⁹, where R⁹ is alkylof 1-4 carbons or aryl; (CH₂)_(n) OR⁹, where n is an integer of 1-4;OR¹⁰, where R¹⁰ is H or alkyl of 1-4 carbons; (CH₂)_(n) OR¹⁴, where R¹⁴is the residue of an amino acid after the hydroxyl group of the carboxylgroup is removed; OR¹⁴, NR⁷ R⁸ ; (CH₂)_(n) NR⁷ R⁸, and O(CH₂)_(n) NR⁷ R⁸; and either

(1) R⁷ and R⁸ independently are H or alkyl of 1-4 carbons; or

(2) R⁷ and R⁸ are combined together to form a linking group of thegeneral formula --(CH₂)₂ --X¹ --(CH₂)₂ --, where X¹ is O, S or CH₂ ;

b) R² is selected form the group consisting of H, SO₂ R⁹, CO₂ R⁹,C(═O)R⁹, alkyl of 1-8 carbons, alkenyl of 1-8 carbons, alkynyl of 1-8carbons, and a monosaccharide of 5-7 carbons, wherein each hydroxylgroup of said monosaccharide is independently selected from the groupconsisting of unsubstituted hydroxyl and a replacement moiety replacingsaid hydroxyl group selected from the group consisting of H, alkyl of1-4 carbons, alkylcarbonyloxy of 2-5 carbons, and alkoxy of 1-4 carbons;wherein either

1) each alkyl of 1-8 carbons, alkenyl of 1-8 carbons, or alkynyl of 1-8carbons is unsubstituted; or

2) each alkyl of 1-8 carbons, alkenyl of 1-8 carbons, or alkynyl of 1-8carbons independently is substituted with 1-3 groups selected from thegroup consisting of aryl of 6-10 carbons, heteroaryl, F, Cl, Br, I, CN,NO₂, OH, OR⁹, O(CH₂)_(n) NR⁷ R⁸, OCOR⁹, OCONHR⁹, O-tetrahydropyranyl,NH₂, NR⁷ R⁸, NR¹⁰ COR⁹ ; NR¹⁰ CO₂ R⁹, NR¹⁰ CONR⁷ R⁸, NHC(═NH)NH₂, NR¹⁰SO₂ R⁹ ; S(O)_(y) R¹¹, wherein R¹¹ is H, alkyl of 1-4 carbons, aryl of6-10 carbons, or heteroaryl, and y is 1 or 2; SR¹¹, CO₂ R⁹, CONR⁷ R⁸,CHO, COR⁹, CH₂ OR⁷, CH₂ OR⁹, CH═NNR¹¹ R¹², CH═NOR¹¹, CH═NR⁹,CH═NNHCH(N═NH)NH₂ ; SO₂ NR¹² R¹³ ; wherein either

(1a) R¹² and R¹³, independently, are H, alkyl of 1-4 carbons, aryl of6-10 carbons, or heteroaryl; or

(2a) R¹² and R¹³ are combined together to form a --(CH₂)₂ --X¹ --(CH₂)₂linking group;

PO(OR¹¹)₂, NHR¹⁴, NR¹⁰ R¹⁴, OR¹⁴, and a monosaccharide of 5-7 carbonswherein each hydroxyl group of said monosaccharide is independentlyselected from the group consisting of unsubstituted hydroxyl and areplacement moiety replacing said hydroxyl group selected from the groupconsisting of H, alkyl of 1-4 carbons, alkylcarbonyloxy of 2-5 carbons,and alkoxy of 1-4 carbons;

c) each R³ and R⁴, independently, is selected from the group consistingof H, aryl of 6-10 carbons, heteroaryl, F, Cl, Br, I, CN, CF₃, NO₂, OH,OR⁹, O(CH₂)_(n) NR⁷ R⁸, OCOR⁹, OCONHR⁹, NH₂, (CH₂)_(n) OR⁹, (CH₂)_(n)OR¹⁰, (CH₂)_(n) OR¹⁴, OR¹⁴, NHR¹⁴, NR⁷ R⁸, NR⁷ (CH₂)_(n) NR⁷ R⁸, NR¹⁰COR⁹, NR¹⁰ CONR⁷ R⁸, SR¹¹, S(O)_(y) R¹¹, CO₂ R⁹, COR⁹, CONR⁷ R⁸, CHO,CH═NOR¹¹, CH═NR⁹, CH═NNR¹¹ R¹², (CH₂)_(n) SR⁹, (CH₂)_(n) S(O)_(y) R⁹ ;CH₂ SR¹⁵, where R¹⁵ is alkyl of 1-4 carbons; CH₂ S(O)_(y) R¹⁴, (CH₂)_(n)NR⁷ R⁸, (CH₂)_(n) NHR¹⁴, alkyl of 1-8 carbons, alkenyl of 1-8 carbons,and alkynyl of 1-8 carbons; and either

1) each alkyl of 1-8 carbons, alkenyl of 1-8 carbons or alkynyl of 1-8carbons is unsubstituted; or

2) each alkyl of 1-8 carbons, alkenyl of 1-8 carbons, or alkynyl of 1-8carbons in independently substituted as described in b)2) above;

d) R⁵ is selected from the group consisting of alkyl of 1-8 carbons,alkenyl of 1-8 carbons, and alkynyl of 1-8 carbons; and either

1) each alkyl, alkenyl, or alkenyl group is unsubstituted; or

2) each alkyl, alkenyl, or alkynyl group is substituted with 1-3 groupsselected from the group consisting of F, Cl, Br, I, CN, CF₃, NO₂, OH,OR⁹, O(CH₂)_(n) NR⁷ R⁸, OCOR⁹, OCONHR⁹, NH₂, (CH₂)_(n) OR⁹, (CH₂)_(n)OR¹⁴, NR⁷ R⁸, NR⁷ (CH₂)_(n) NR⁷ R⁸, NR¹⁰ COR⁹, NR¹⁰ CONR⁷ R⁸, SR¹¹,S(O)_(y) R¹¹, CO₂ R⁹, COR⁹, CONR⁷ R⁸, CHO, CH═NOR¹¹, CH═NR⁹, CH═NNR¹¹R¹², (CH₂)_(n) SR⁹, (CH₂)_(n) S(O)_(y) R⁹, CH₂ SR¹⁵, CH₂ S(O)_(y) R¹⁴,(CH₂)_(n) NR⁷ R⁸, and (CH₂)_(n) NHR¹⁴ ;

e) X is selected from the group consisting of --N--, --O--, --S--,--S(═O)--, --S(═O)₂ --, alkylene of 1-3 carbons, --C(═O)--,--C(R²)═C(R²)--, --C(R²)₂ --, --CH═CH--, --CH(OH)-- CH(OH)--,--C(═NOR¹¹)--, --C(OR¹¹)(R¹¹)--, --C(═O)CH(R¹⁵)--, --CH(R¹⁵)C(═O)--;--CH₂ --Z--, --Z--CH₂ --, --CH₂ ZCH₂ --, where Z is selected from thegroup consisting of --C(OR¹¹)(R¹¹)--, O, S, C(═O), and NR¹¹ ; andalkylene of 1-3 carbons substituted with a group selected from the groupconsisting of one R⁵ substituent group, SR¹⁰, OR¹⁰, OR¹⁴, R¹⁵, phenyl,naphthyl, and arylalkyl of 7-14 carbons.

As used herein, the term "aryl" means monocyclic and polycyclic aromaticgroups including, for example, phenyl, naphthyl, biphenyl, and xylylgroups. Aryl groups may be unsubstituted or substituted with, forexample, alkyl and halogen groups. Halogens include fluorine, chlorine,bromine, and iodine. Preferred are aryl groups which contain 6-10carbons. Phenyl and naphthyl groups are particularly preferred.

As used herein, the term "heteroaryl" means an aryl moiety whichcontains at least one basic nitrogen atom and 0-4 heteroatoms selectedfrom O, S, and N. Examples of heteroaryl groups include pyrrolyl,pyranyl, thiopyranyl, furyl, imidazolyl, pyridyl, thiazolyl, triazinyl,phthalimido, indolyl. purinyl, and benzothiazolyl.

As used herein with reference to the definition of R¹⁴, the term "aminoacid" means a molecule containing both an amino group and a carboxylgroup. It includes an "α-amino acid" which has its usual meaning as acarboxylic acid which bears an amino functionality on the carbonadjacent to the carboxyl group. α-Amino acids can be naturally occurringor non-naturally occurring. Amino acids also include "dipeptides" whichare defined herein as two amino acids which are joined in a peptideamide linkage. Thus, constituents of dipeptides are not limited toα-amino acids, and can be any molecule containing both an amino groupand a carboxyl group. Preferred are α-amino acids, dipeptides such aslysyl-β-alanine, and aminoalkanoic acids of 2-8 carbons, e.g.,3-dimethylaminobutyric acid.

Preferred "alkyl", "alkenyl", and "alkynyl" groups contain 1-4 carbonatoms.

Preferred R¹ groups include H, alkyl of 1-4 carbons, substituted orunsubstituted phenyl, OR¹⁰, and O(CH2)_(n) NR⁷ R⁸. Preferred phenylsubstituents include alkyl of 1-4 carbons, and halogen. Most preferredis H.

Preferred R² groups include H, C(═O)R⁹, alkyl of 1-8 carbons, and alkylof 1-8 carbons substituted with one OR⁹, OH, OCOR⁹, NR⁷ R⁸, NH₂, NR¹⁰COR⁹, or NR¹⁰ R¹⁴ group. Most preferred is H.

Preferred R³ and R⁴ groups include H, halogen, CN, OH, OR⁹, OR¹⁴, NH₂,NR⁷ R⁸, (CH₂)_(n) OR¹⁰, (CH₂)_(n) OR¹⁴, COR⁹, NR¹⁰ COR⁹, NHR¹⁴, andO(CH₂)_(n) NR⁷ R⁸. Most preferred is H.

Preferred R⁵ groups include H, and alkyl of 1-4 carbons. Most preferredis H.

Preferred X groups include --N--, --O--, --S--, alkylene of 1-3 carbons,--C═O--, --CH₂ --Z-- and --Z--CH₂ --. Most preferred are --N--, --O--,--S--, and --CH₂ -- groups.

III. Fused Pyrrolo[2,3-c]carbazole-6-one Utilities

Our fused pyrrolo[2,3-c]carbazole-6-ones have evidenced a panoply ofimportant functional activities which find utility in a variety ofsettings, including both research and therapeutic arenas. For ease ofpresentation, and in order not to limit the range of utilities for whichthese compounds can be characterized, the preferred activities of thefused pyrrolo[2,3-c]carbazole-6-ones can be generally described asfollows:

A. Enhancement of IFN-γ induction of MHC molecules;

B. Potentiation of function and/or survival of trophic factor responsivecells.

Enhancement of IFN-γ induction of MHC molecules can preferably beestablished using a human monocyte cell line that responds to IFN-γ; aparticularly preferred cell line is available from the American TypeCulture Collection (ATCC), referred to as THP-1, under accession numberATCC TIB-202. IFN-γ is known to induce expression of the three MHC IIheterodimers, HLA-DP, HLA-DQ and HLA-DR; in THP-1cells. Potentiation offunction and/or survival of trophic factor responsive cells, e.g., cellsof neuronal lineage, can be preferably established using a culturedspinal cord choline acetyltransferase ("ChAT") assay.

As used herein, the term "potentiation" when used to modify the terms"function" and "survival" means a positive alteration or change.Potentiation which is positive can also be referred to herein as an"enhancement" or "enhancing."

As used herein, the terms "enhance" or "enhancing" or enhancement whenused to modify the terms "function" or "survival" or "induction" meansthat the presence of a fused pyrrolo[2,3-c]carbazole-6-one has acomparatively greater effect on the function and/or survival of atrophic factor responsive cell or, in the case of IFN-γ, induction ofMHC molecules, than a comparative cell not presented with the fusedpyrrolo[2,3-c]carbazole-6-one.

As used herein the term "neuron," "cell of neuronal lineage" and"neuronal cell" includes, but is not limited to, a heterogeneouspopulation of neuronal types having singular or multiple transmittersand/or singular or multiple functions; preferably, these are cholinergicneurons. As used herein, the phrase "cholinergic neuron" means neuronsof the Central Nervous System (CNS) and Peripheral Nervous System (PNS)whose neurotransmitter is acetylcholine; exemplary are basal forebrainand spinal cord neurons.

As used herein a "trophic factor" is a molecule that directly orindirectly affests the survival or function of a trophic factorresponsive cell. Exemplary trophic factors include Ciliary NeurotrophicFactor (CNTF), basic Fibroblast Growth Factor (bFGF), insulin andinsulin-like growth factors (e.g., IGF-I, IGF-II, IGF-III), inteferons,interleukins, cytokines, and the neurotrophins, including Nerve GrowthFactor (NGF), Neurotrophin-3 (NT-3), Neurotrophin-4/5 (NT-4/5) and BrainDerived Neurotrophic Factor (BDNF).

A "trophic factor-responsive cell," as defined herein, is a cell whichincludes a receptor to which a trophic factor can specifically bind;examples include neurons (e.g., cholinergic neurons) and non-neuronalcells (e.g., monocytes and neoplastic cells).

As used herein, "trophic factor activity" and "trophic factor inducedactivity" are defined as any response which directly or indirectlyresults from the binding of a trophic factor (e.g., NT-3) to a cellcomprising a trophic factor receptor.

As used in the phrases "trophic factor activity" and "trophicfactor-induced activity," the term "trophic factor" includes bothendogenous and exogenous trophic factors, where "endogenous" refers to atrophic factor already present and "exogenous" refers to a trophicfactor added to a system. As defined, "trophic factor induced activity"includes activity induced by (1) endogenous trophic factors; (2)exogenous trophic factors; and (3) a combination of endogenous andexogenous trophic factors.

A. Enhancement of IFN-γ Induction of MHC Molecules

The compounds of the invention can be used to enhance IFN-γ induction ofMHC molecules. IFN-γ has shown effectiveness in the treatment of virusinfections and certain tumors. Due to its dose limiting side effects,however, the utility of IFN-γ has been limited. In an immunocompromisedsituation, e.g., in a patient evidencing viral infection, enhancement ofan IFN-γ mediated immune response would be beneficial, given that IFN-γinduces expression of MHC molecules. Thus, the compounds of thisinvention which enhance the ability of endogenous IFN-γ or exogenouslyadministered IFN-γ to induce MHC expression are of benefit.

As detailed in Section V below, the ability of a fusedpyrrolo[2,3-c]carbazole-6-one to enhance IFN-γ induction of MHCmolecules is preferably assessed using the THP-1 cell line. This cellline evidences expression of the MHC II heterodimer HLA-DR. Comparingthe expression of HLA-DR in the presence of IFN-γ and IFN-γ plus one ormore fused pyrrolo[2,3-c]carbazole-6-ones of the present inventionprovides a rapid and efficient method for determination of enhancementof IFN-γ induction of MHC molecules can be assessed.

The compounds of this invention can be used in the development of invitro models of enhancement of expression of MHC molecules, function,identification, or for the screening of other synthetic compounds whichhave activities similar to that of the fusedpyrrolo[2,3-c]carbazole-6-ones. The compounds can be utilized in aresearch environment to investigate, refine and determine moleculartargets associated with functional responses. For example, byradiolabelling a fused pyrrolo[2,3-c]carbazole-6-one associated with aspecific cellular function (e.g., HLA-DR induction), the target entityto which the fused pyrrolo[2,3-c]carbazole-6-one binds can beidentified, isolated, and purified for characterization. In yet anotherexample, a fused pyrrolo[2,3-c]carbazole-6-one can be used as ascreening tool to discover agents which have marginal activity, but whencombined with at least one disclosed fused pyrrolo[2,3-c]carbazole-6-oneare capable of enhancing IFN-γ induction of MHC molecules. Because thedisclosed fused pyrrolo[2,3-c]carbazole-6-ones are useful in enhancingIFN-γ induction of MHC molecules, the disclosed compounds beneficiallylend themselves to utility as therapeutic agents. Such enhancement is ofvalue in an immunocompromised patient.

B. Potentiation of function and/or survival of trophic factor responsivecells

The fused pyrrolo[2,3-c]carbazole-6-ones of this invention can be usedto enhance the function and/or survival of cells of neuronal lineage.The fused pyrrolo[2,3-c]carbazole-6-ones can be utilized individually orwith other fused pyrrolo[2,3-c]carbazole-6-ones, or in combination withother beneficial molecules such as indolocarbazoles which also have theability to potentiate the function and/or survival of a designated cell.In situations where the fused pyrrolo[2,3-c]carbazole-6-one is intendedto enhance a biological activity, e.g., neurotrophin activity, exogenousneurotrophins such as NT-3 may be utilized in conjunction with the fusedpyrrolo[2,3-c]carbazole-6-one.

A variety of neurological disorders are characterized by neuronal cellswhich are dying, injured, functionally comprised, undergoing axonaldegeneration, at risk of dying, etc. These disorders include, but arenot limited to: Alzheimer's; motor neuron disorders (e.g., amyotrophiclateral sclerosis); Parkinson's; cerebrovascular disorders (e.g.,multiple sclerosis; peripheral neuropathies (e.g., those affecting DRGneurons in chemotherapy-associated peripheral neuropathy); disordersinduced by excitatory amino acids; disorders associated with concussiveor penetrating injuries of the brain or spinal cord.

As described in Section V below, the ability of a fusedpyrrolo[2,3-c]carbazole-6-one to enhance the function and/or survival ofcells of a neuronal lineage can be determined by employing a basalforebrain ChAT activity assay. ChAT catalyzes the synthesis of theneurotransmitter acetylcholine and is considered an enzymatic marker fora functional cholinergic neuron. A functional neuron is also capable ofsurvival. Enhancement of a neurotrophin such as NT-3 can be determinedby comparing the functional activity of the neurotrophin with or withoutthe fused pyrrolo[2,3-c]carbazole-6-one present.

Pharmaceutically acceptable salts of the fusedpyrrolo[2,3-c]carbazole-6-ones also fall within the scope of the presentinvention. The term "pharmaceutically acceptable salts" as used hereinmeans in inorganic acid addition salt such as hydrochloride, sulfate,and phosphate, or an organic acid addition salt such as acetate,maleate, fumarate, tartrate, and citrate. Examples of pharmaceuticallyacceptable metal salts are alkali metal salts such as sodium salt andpotassium salt, alkaline earth metal salts such as magnesium salt andcalcium salt, aluminum salt, and zinc salt. Examples of pharmaceuticallyacceptable ammonium salts are ammonium salt and tetramethylammoniumsalt. Examples of pharmaceutically acceptable organic amine additionsalts are salts with morpholine and piperidine. Examples ofpharmaceutically acceptable amino acid addition salts are salts withlysine, glycine, and phenylalanine.

Compounds provided herein can be formulated into pharmaceuticalcompositions by admixture with pharmaceutically acceptable nontoxicexcipients and carriers. Such compositions can be prepared for use inparenteral administration, particularly in the form of liquid solutionsor suspensions; or oral administration, particularly in the form oftablets or capsules; or intranasally, particularly in the form ofpowders, nasal drops, or aerosols; or dermally, via, for example,trans-dermal patches.

The composition can be conveniently administered in unit dosage form andmay be prepared by any of the methods will known in the pharmaceuticalart, for example, as described in Remington's Pharmaceutical Sciences(Mack Pub. Co., Easton, Pa., 1980). Formulations for parenteraladministration may contain as common excipients sterile water or saline,polyalkylene glycols such as polyethylene glycol, oils and vegetableorigin, hydrogenated naphthalenes and the like. In particular,biocompatible, biodegradable lactide polymer, lactide/glycolidecopolymer, or polyoxyethylene-polyoxypropylene copolymers may be usefulexcipients to control the release of the active compounds. Otherpotentially useful parenteral delivery systems for these activecompounds include ethylene-vinyl acetate copolymer particles, osmoticpumps, implantable infusion systems, and liposomes. Formulations forinhalation administration contain as excipients, for example, lactose,or may be aqueous solutions containing, for example,polyoxyethylene-9-lauryl ether, glycocholate and deoxycholate, or oilysolutions for administration in the form of nasal drops, or as a gel tobe applied intranasally. Formulations for parenteral administration mayalso include glycocholate for buccal administration, a salicylate forrectal administration, or citric acid for vaginal administration.Formulations for trans-dermal patches are preferably lipophilicemulsions.

The compounds of this invention can be employed as the sole active agentin a pharmaceutical composition. Alternatively, they can be used incombination with other active ingredients, e.g., synthetic IFN-γ and/orother growth factors which facilitate potentiation of NT-3 such as thosedisclosed in U.S. Pat. No. 5,468,872 and International Publication No.WO 95/07911 (publication date: Mar. 23, 1995).

The concentrations of the compounds of this invention in a therapeuticcomposition can vary. The concentration will depend upon factors such asthe total dosage of the drug to be administered, the chemicalcharacteristics (e.g., hydrophobicity) of the compounds employed, andthe route of administration. The compounds of this invention typicallyare provided in an aqueous physiological buffer solution containingabout 0.1 to 10% w/v compound for parenteral administration. Typicaldose ranges are from about 1 μg/kg to about 1 g/kg of body weight perday; a preferred dose range is from about 0.01 mg/kg to 100 mg/kg ofbody weight per day. A preferred dosage of drug to be administered islikely to depend on variables such as the type and extent of progressionof the disease or disorder, the overall health status of the particularpatient, the relative biological efficacy of the compounds selected, andformulation of the compound excipient, and its route of administration.

IV. General Description of the Synthetic Processes

Two synthetic routes were employed to prepare the fusedpyrrolo[2,3-]carbazole-6-one derivatives of the invention. In Method A(FIG. 2) a 2-(aryl) or 2-(heteroaryl)indole derivative (1-4) which iseither unsubstituted or substituted at carbons 4-7 (inclusive) of theindole ring (R³) or substituted or unsubstituted in the (hetero)arylportion (R⁴) is reacted with maleimide in the presence of a catalystsuch as, trifluoroacetic acid (TFA) to give the fusedpyrrolocarbazole-6-one derivatives of Formula I (Examples I-IV).Additional Lewis acid catalysts, such as SnCl₄, AlCl₃, EtAlCl₂, or Et₂AlCl may also be used to effect the reaction. The reaction may also berun in a solvent such as TFA, toluene, CH₂ Cl₂ or 1,2-dichloroethane.

The bi-aryl indole intermediates, 2,2'-biindole 1 (X═N, R², R³, R⁴ ═H),2-(2-furyl)indole 2 (X═O, R², R³, R⁴ ═H) and 2-(benzothienyl)indole 3(X═S, R², R³, R⁴ ═H) may be prepared using standard literatureprocedures (Hudkins, R. L.; et. al J. Org. Chem., 1995, 60, 6218) (FIG.2). 2-(2-Indenyl)indole 4 (FIG. 3) (X═CH₂, R², R³, R⁴ ═H), or2-(2-indenyl)indole derivatives substituted with an R³ or R⁴ group, maybe prepared by reacting 1-carboxy-2-(tributylstannyl)indole 5, or1-carboxy-2-(tributylstannyl)indole substituted with an R³ group(Hudkins, R. L. et. al J. Org. Chem., 1995, 60, 6218) with 2-bromoindene6 (J. Org. Chem., 1982, 47, 705) or a 2-bromoindene substituted with anR⁴ group. Alternatively, 2-(2-indenyl)indole 4 (X═CH₂, R², R³, R⁴ ═H),or 2-(2-indenyl)indole derivatives substituted with an R³ or R⁴ group,may be prepared by reaction of 1H-indole or a derivative thereofcontaining an R³ group, protected as a lithium indole-1-carboxylateintermediate (Tetrahedron Lett. 26:5935 (1985)), then treated with astrong base, such as t-BuLi, then alkylated with an appropriate2-indanone, or 2-indanone derivative substituted with an R⁴ group togive the corresponding tertiary alcohol 7 (FIG. 4). The resultingtertiary alcohol 7 is treated with a dilute acid (e.g., 2N HCl inacetone) to give the corresponding 2-(2-indenyl)indole 4 (U.S. Pat. No.5,475,110). Using other Benzocycloalkan-2-ones such as 2-tetralone inthe reaction sequence shown in FIG. 4 will give2-(2-(3,4-dihydronaphthyl)indole 8 (X═CH₂ CH₂, R², R³, R⁴ ═H) (U.S. Pat.No. 5,475,110). The palladium-catalyzed cross-coupling methodology(Stille reaction) may be used to prepare other derivatives, for example,where X in FIG. 3 has 1-3 carbons (inclusive), by coupling the2-(trifluoromethanesulfonate)- or the 2-iodo- or 2-bromovinyl derivativeof the corresponding cyclic ketone with1-carboxy-2-tributylstannylindole to give2-(2-benzocycloalkenyl)indoles.

The starting 1H-indole derivative described previously is converted to a1-substituted indole derivative (R² not H) by standard methodology, forexample, by treatment of the 1H-indole with base and an alkylating agentto give a 1-substituted indole. In these examples, the indole derivativecan be directly treated with a strong base (e.g., t-BuLi, sec-BuLi,n-BuLi, lithium diisopropylamide) followed by alkylation with a2-indanone derivative to give the corresponding tertiary alcohol 7,which includes R² substitutents in position one of the indole ring. The2-(aryl)- or 2-(heteroaryl)indole derivative (1-3), 2-(2-indenyl)indole4, or 2-(2-(1,2-dihydronaphthyl)indole 8 may be converted tointermediates which contain R² substituents in position one of theindole ring by the method described above for indole derivatives.

Compounds of general formulae I and II which contain R¹ groups, not ═H,may be prepared by starting with the appropriate R¹ substitutedmaleimide (FIG. 2, Method A). Compounds of general formulae I and II, inwhich R¹ is hydrogen, can be alkylated in the presence of base (e.g.,hydrides, alkoxides, hydroxides of alkali or alkaline earth metals, orof organo-lithium compounds) by treatment with R¹ L in which L is aleaving group such as a halogen, mesylate or tosylate to give a fusedpyrrolocarbazole-6-one derivative which has an R¹ group bound to thelactam nitrogen. Compounds of general formulae I and II, in which R⁵ ishydrogen, may be converted to derivatives where one or two R⁵ groups maybe added by treatment of a fused pyrrolocarbazole-6-one derivative withone equivalent or an excess of a strong base (e.g., hydrides, alkoxides,hydroxides of alkali or alkaline earth metals, or of organo-lithiumcompounds) with R⁵ L in which L is a leaving group such as a halogen, orby condensation with an R⁵ containing ketone or aldehyde carbonylderivative to give a fused pyrrolocarbazole-6-one derivative which hasone or two an R⁵ groups. The derivatives from the ketone or aldehydecondensation reactions would give vinyl derivatives at R⁵.

The indole derivatives are prepared using standard methodology (U.S.Pat. No. 3,976,639; U.S. Pat. No. 3,732,245; The Chemistry ofHeterocyclic Compounds, Indoles Parts One and Two; Houlihan Ed.,Wiley-Interscience (1972)). The 2-indanone derivatives can be preparedusing previously described procedures (see U.S. Pat. No. 4,192,888; U.S.Pat. No. 4,128,666; J. Am. Chem. Soc. 89:4524 (1967); Tetrahedron Lett.43:3789 (1974); Chem Ber. 122:1791 (1989); Can. J. Chem. 60:2678 (1982);Helvetica Chimica Acta 70:1791 (1987); Chem. Pharm. Bull. 33:3336(1985); J. Org. Chem. 55:4835 (1990); Tetrahedron 45:1441 (1989);Synthesis 818 (1981)).

In Method B (FIG. 2), a 2-(heteroaryl)indole derivative (1-3), or2-(aryl)indole derivative such as 2-(2-indenyl)indole 4 is reacted withethyl cis-β-cyanoacrylate in the presence of a catalyst such as SnCl₄,AlCl₃, EtAlCl₂, Et₂ AlCl or TFA in CH₂ Cl₂, C₂ H₄ Cl₂ or toluene assolvent to give the 6-oxo carbazole compounds of formula I of theinvention.

Compounds of Formula II are prepared as outlined in FIG. 5. Addition of2-(aryl)- or 2-(heteroaryl)indolylzinc reagents (Tetrahedron Lett.,1994, 35, 793; Tetrahedron Lett., 1994, 35, 7123; Tetrahedron Lett.,1993, 34, 5955; Tetrahedron Lett., 1993, 34, 6245) to succinimide, or anR¹ substituted succinimide derivative, via a Reformatzsky type reaction(Synthesis, 1975, 685) followed by dehydration would give compounds ofthe general structure 9. Palladium catalyzed ring closure (U.S. Pat. No.5,475,110; Tetrahedron Lett., 1993, 34, 8361) would yieldpyrrolo[2,3-c]carbazole compounds of Formula II.

Compounds in which X═(C═O) (general structure 10) are prepared byoxidation of derivatives of general Formula I (or II) where X═CH₂, usingstandard oxidizing reagents (e.g., SeO₂, CrO₃, Na₂ CrO₇, or MnO₂) (FIG.6). Alternatively, 2-(2-indenyl)indole 4 may be oxidized to2-(2-(1-oxoindenyl)indole and used to prepare compounds of Formula I orII where X═(C═O) by the methods shown in FIGS. 2 and 5. Alternatively,2-(2-(1-oxoindenyl)indole 11 may prepared using the palladium-catalyzedcross-coupling methodology (FIG. 3) by coupling1-carboxy-2-tributylstannylindole 5 or its derivatives with2-(trifluoromethanesulfonyl)oxyinden-1-one or 2-bromoinden-1-one 12(FIG. 7) (J. Org. Chem., 1994, 59, 3453) or one of its derivatives.Compounds of the general structure 10 (X═(C═O)) may undergo a variety ofolefination, addition and condensation reactions known to those skilledin the art of organic synthesis to give derivatives, for example, butnot limited to, X═(C═C(R²)²), C(R²)², C(OR¹¹)(R¹¹). Fusedpyrrolocarbazole-6-one derivatives where X is S(═O) or S(═O)₂ may beprepared by oxidation of X═S derivatives in a manner similar to X═(C═O).

EXAMPLES V. Specific Description of the Synthetic Processes

The following examples are presented for purposes of illustration andare not to be construed as limiting the scope of the invention in anyway.

A. Example I: 5H, 7H,13H-Benzofurano[2,3-a]pyrrolo[2,3-c]carbazole-6(6H)one (X═O; R¹, R², R³,R⁴, R⁵ ═H)

A mixture of 2-(2-benzofuryl)indole 2 (250 mg; 1.0 mmol) and maleimide(110 mg; 1.2 mmol) in trifluoroacetic acid (2 mL) was heated in a sealedreaction vial at 125° C. for 18 h. The solid precipitated was collected,washed with TFA and dried to give 150 mg (48%) of product.Recrystallization (THF) gave a tan solid; mp>300° C., MS (ES⁺) 312 (M⁺),¹ H NMR (DMSO-d₆) δ 4.00 (s, 2H), 4.13 (s, 2H), 7.12 (t, 1H), 7.37 (t,2H), 7.45 (t, 2H), 7.71 (d, 1H), 7.95 (d, 1H), 8.54 (d, 1H), 10.12 (s,1H), 11.79 (s, 1H). Anal. calcd for C₂₀ H₁₂ N₂ O₂.0.4 H₂ O; C, 75.18; H,4.04; N, 8.77. Found: C, 75.29, H, 3.86, N, 8.60.

B. Example II: 5H, 7H,13H-Benzothieno[2,3-a]pyrrolo[2,3-c]carbazole-6(6H)one (X═S; R¹, R², R³,R⁴, R⁵ ═H)

A mixture of 2-(2-benzothienyl)indole 3 (100 mg, 0.4 mmol) and maleimide(40 mg; 0.4 mmol) in trifluoroacetic acid (2 mL) was heated in a sealedreaction vial at 125° C. for 16 h. The solid precipitated was collected,washed with cold methanol and dried to give 80 mg (58%) of product.Recrystallization (THF) gave a tan solid; mp>300° C., MS (ES⁺) 328 (M⁺),¹ H NMR (DMSO-d₆) δ 4.10 (s, 2H), 7.20 (t, 1H), 7.40-7.60 (m, 4H), 8.10(d, 1H), 8.80 (m, 1H), 10.86 (s, 1H), 11.80 (s, 1H). Anal. calcd for C₂₀H₁₂ N₂ SO.0.5 H₂ O; C, 71.20; H, 3.88; N, 8.30. Found: C, 70.86, H,3.61, N, 8.39.

C. Example III: 5H, 7H, 12H,13H-Indolo[2,3-a]pyrrolo[2,3-c]carbazole-6(6H)one (X═N; R¹, R², R³, R⁴,R⁵ ═H)

(1) Method A

To a mixture of 2-2'-biindole 1 (250 mg; 1.0 mmol) and maleimide (110mg; 1.2 mmol) suspended in toluene (50 mL) was added trifluoroaceticacid (0.5 mL). The solution was heated at reflux for 18 h., cooled tort, and concentrated to approximately 20 mL. The solution was cooled inan ice bath, the solid precipitate was collected, washed with cold etherand dried to give 150 mg (55%) of product. Purification by columnchromatography (EtOAc: hexanes; 2:1) gave a brown-tan solid, mp>320° C.,MS (ES⁺) 311 (M⁺), ¹ H NMR (DMSO-d₆) δ 4.00 (s, 2H), 7.17-7.22 (m, 2H),7.37-7.42 (m, 2H), 7.67 (d, 2H), 8.03 (d, 1H), 8.58 (d, 1H), 10.87 (s,1H), 10.92 (s,1H), 11.18 (s, 1H). Anal. calcd for C₂₀ H₁₂ N₂ O₂.0.5 H₂O; C, 74.99; H, 4.41; N, 13.12. Found: C, 75.24, H,4.02, N, 13.05.

(2) Method B

A mixture of 2-2'-biindole 1 (100 mg; 0.43 mmol) and ethylcis-β-cyanoacrylate (50 mg; 0.4 mmol) in methylene chloride (10 mL) wasadded 25 mL of SnCl₄. The mixture was stirred at rt for 30 min. Thesuspension was cooled on an ice bath, the solid collected, washed withcold ether and dried to give 36 mg (27%) of product. Purification bycolumn chromatography (EtOAc: hexanes; 2:1) gave a brown-tan solid;mp>320° C., MS (ES⁺) 311 (M⁺), ¹ H NMR (DMSO-d₆) δ 4.00 (s, 2H),7.17-7.22 (m, 2H), 7.37-7.42 (m, 2H), 7.67 (d, 2H), 8.03 (d, 1H), 8.58(d, 1H), 10.87 (s, 1H), 10.92 (s,1H), 11.18 (s, 1H).

This compound showed identical spectral and analytical characteristicsas that prepared by Method A.

D. Example IV: 5H, 7H, 12H,13H-Indeno[2,3-a]pyrrolo[2,3-c]carbazole-6(6H)one (X═CH₂ ; R¹, R², R³,R⁴, R⁵ ═H)

(1) Method A

A mixture of 2-(2-indenyl)indole 4 (300 mg, 1.3 mmol) and maleimide (160mg; 1.6 mmol) in trifluoroactic acid (2 mL) was heated in a sealedreaction vial at 160° C. for 18 h. The solution was evaporated and thesolid dissolved in ethyl acetate, then washed with water and dried(MgSO₄) to give brown solid product. The crude product waschromatographed (silica gel, EtOac: hexanes; 1:1) to give a productwhich was treated with THF and filtered. The concentrated residue wastritutrated with MeOH to give the product; mp 275°-280° C., MS (ES⁺) 310(M⁺), ¹ H NMR (DMSO-d₆) δ 4.00 (s, 2H), 4.13 (s, 2H), 7.17 (t, 1H),7.25-7.42 (m, 3H), 7.50 (d, 1H), 7.71 (d, 1H), 8.00 (d, 1H), 8.37 (d,1H), 10.75 (s, 1H), 11.33 (s, 1H). IR (KBr) 1650-1700 cm⁻¹. Anal. calcdfor C₂₁ H₁₄ N₂ O.0.7 H₂ O; C, 78.10; H, 4.81; N, 8.65. Found: C, 78.13,H, 4.41, N, 8.10.

(2) Method B

A mixture of 2-(2-indenyl)indole 4 (75 mg; 0.32 mmol) and ethylcis-β-cyanoacrylate (81 mg; 0.64 mmol) in trifluoroacetic acid (1 mL)was heated in a sealed reaction vial at 120° C. for 1 h., followed by 4h at 160° C. The mixture was evaporated at reduced pressure and theresidue was triturated with ether. The resulting solid waschromatographed (silica gel; EtOAc: hexanes; 1:1) to give 12 mg (12%) oftan solid product; mp 275°-280° C., MS (ES⁺) 310 (M⁺). This compoundshowed identical spectral data as that prepared in Method A.

E. Example V: Enhancement by Fused Pyrrolo[2,3-c]carbazole-6-ones of theInduction by IFN-γ of the MHC II Antigen HLA-DR

A human cell line derived from human monocytes, THP-1 (ATCC TIB 202)that responds to IFN-γ, was used to demonstrate enhancement of HLA-DR bythe fused pyrrolo[2,3-c]carbazole-6-ones.

THP-1 cells were grown in RPMI 1640 medium containing 20 uMmercaptoethanol and 10% fetal bovine serum at 37° C. in an atmosphere of5% CO2:95% air at 100% humidity. For determination of enhancement ofHLA-DR by the compounds of the invention, cells were either leftuntreated as controls, treated with IFN-γ only at 100 units/ml, ortreated with compounds of the invention at 1 uM final concentration for30 min. prior to the addition of IFN-γ at 100 units/ml. Duplicatecultures were used in all experiments. The treated THP-1 cells wereincubated at 37° C. for 48 hours and then prepared for analysis ofHLA-DR by Flow Cytometry. Induction of HLA-DR was performed by standardprocedures as described in Inteferons and Other Regulatory Cytokines,Edward De Maeyer and Jacqueline De Maeyer Guignard, Chapter 9, JohnWiley & Sons, New York, 1988. Cells were prepared for flow cytometry andanalyzed for HLA-DR by flow cytometry as instructed in Current Protocolsin Immunology, Vol. 1, pages 5.0.1-5.8.8, John Wiley & Sons, 1994. Onemillion cells from each treatment were collected by centrifugation andwashed twice with phosphate-buffered saline (PBS). The cells wereresuspended in 100 ul of PBS containing 10 ug of purified rabbit IgG toblock non-specific sites on the cell surface. After 20 min. on ice, 20ul of anti-HLA-DR monoclonal antibody tagged with the fluorescent labelFITC was added and the cells left on ice an additional 30 min to allowthe antibody to bind to the HLA-DR. The cells were then washed 2 timeswith PBS each wash and fixed in 0.5 ml of 0.5% paraformaldehyde. Thefixed cells were stored at 4° C. until analyzed by flow cytometry.

The enhancement of HLA-DR by representative fusedpyrrolo[2,3-c]carbazole-6-ones is shown in FIG. 1. The enhancement ofHLA-DR by IFN-γ alone is designated 100% on the Y axis. There is nosignificant induction of HLA-DR by the representative compounds alone at1 uM (FIG. 1). All of the representative compounds enhance the inductionof HLA-DR by IFN-γ above the induction by IFN-γ alone, i.e. above 100%.The percent enhancement above IFN-γ alone by the four compounds is shownin Table 1. For example, at 2 μM, the compound of Section V(D) (ExampleIV) enhanced IFN-γ induction of HLA-DR by 60% over IFN-γ alone.

                  TABLE 1                                                         ______________________________________                                                Conc. of Fused                                                        Compound                                                                              Pyrrolo[2,3-              Percent                                     of      c]carbazole-6-one,                                                                         Conc. of IFN-γ,                                                                      Enhancement                                 Example #                                                                             uM           Units/ml     of HLA-DR                                   ______________________________________                                        I       --           --            0                                          I       --            100*        100                                         I       1            100          115                                         I       2            100          108                                         II      --           --            0                                          II      --            100*        100                                         II      1            100          133                                         II      2            100          153                                         III     --           --            0                                          III     --            100*        100                                         III     1            100          135                                         III     2            100          130                                         IV      --           --            0                                          IV      --            100*        100                                         IV      1            100          156                                         IV      2            100          160                                         ______________________________________                                         *IFN-γ alone is defined as 100%.                                   

F. Example VI. NT-3 Potentiation of ChAT Activity in Basal ForebrainCultures by Pyrrolo[2,3-c]carbazole-6-ones

The ability of pyrrolo[2,3-c]carbazole-6-ones to potentiate NT-3activity in basal forebrain cultures was determined using cholineacetyltransferase (ChAT) activity as a measure of cholinergic neuronfunction or survival. The compounds alone had no effect on ChATactivity. However, in the presence of NT-3, the representative compoundsgave a dose dependent potentiation of ChAT activity to levels greaterthan those elicited by NT-3 alone. The results shown in Table 2 are theresult of a single application of NT-3 and the compound to be tested onthe day of culture initiation, indicating a prolonged effect on thesurvival or function of basal forebrain cholinergic neurons. The methodsemployed are described in U.S. Pat. No. 5,468,872, Columns 18 and 19.

                  TABLE 2                                                         ______________________________________                                                 % Basal         % NT-3                                               Compound of                                                                            (mean ± SD)  (mean ± SD)                                       Example #                                                                              100 nM    300 nM    100 nM  300 nM                                   ______________________________________                                        NT-3 + I 184 ± 3                                                                              221 ± 2                                                                              113 ± 2                                                                            136 ± 1*                              NT-3 + II                                                                              212 ± 4                                                                               228 ± 13                                                                             130 ± 2*                                                                          140 ± 1*                              NT-3 + III                                                                             180 ± 3                                                                              203 ± 2                                                                              114 ± 2                                                                            129 ± 1*                              ______________________________________                                         NT-3 (100 ng/ml) increased ChAT Activity 163 ± 5% (mean ± SD) over      control untreated cultures. Test compounds alone had basal (100%) level o     activity.                                                                     *p < 0.05, statistically significant when compared to NT3 activity alone      by Dunnett t statistics.                                                 

Those skilled in the art will appreciate that numerous changes andmodifications may be made to the preferred embodiments of the inventionand that such changes and modifications may be made without departingfrom the spirit of the invention. It is therefore intended that theappended claims cover all equivalent variations as fall within the truespirit and scope of the invention. Documents cited throughout thispatent disclosure are hereby incorporated herein by reference.

What is claimed is:
 1. A fused pyrrolo[2,3-c]carbazole-6-one representedby a formula selected from the group consisting of: ##STR4## wherein: a)R¹ is selected from the group consisting of H, alkyl of 1-4 carbonssubstituted or unsubstituted aryl, arylalkyl, heteroaryl,heteroarylalkyl; C(═O)R⁹, where R⁹ is alkyl of 1-4 carbons or aryl;(CH₂)_(n) OR⁹, where n is an integer of 1-4; OR¹⁰, where R¹⁰ is H oralkyl of 1-4 carbons; (CH₂)_(n) OR¹⁴, where R¹⁴ is the residue of anamino acid after the hydroxyl group of the carboxyl group is removed;OR¹⁴, NR⁷ R⁸ ; (CH₂)_(n) NR⁷ R⁸, and O(CH₂)_(n) NR⁷ R⁸ ; and either(1)R⁷ and R⁸ independently are H or alkyl of 1-4 carbons; or (2) R⁷ and R⁸are combined together to form a linking group of the general formula--(CH₂)₂ --X¹ --(CH₂)₂ --, where X¹ O, S or CH₂ ; b) R² is selected formthe group consisting of H, SO₂ R⁹, CO₂ R⁹, C(═O)R⁹, alkyl of 1-8carbons, alkenyl of 1-8 carbons, alkynyl of 1-8 carbons, and amonosaccharide of 5-7 carbons, wherein each hydroxyl group of saidmonosaccharide is independently selected from the group consisting ofunsubstituted hydroxyl and a replacement moiety replacing said hydroxylgroup selected from the group consisting of H, alkyl of 1-4 carbons,alkylcarbonyloxy of 2-5 carbons, and alkoxy of 1-4 carbons; whereineither1) each alkyl of 1-8 carbons, alkenyl of 1-8 carbons, or alkynylof 1-8 carbons is unsubstituted; or 2) each alkyl of 1-8 carbons,alkenyl of 1-8 carbons, or alkynyl of 1-8 carbons independently issubstituted with 1-3 groups selected from the group consisting of arylof 6-10 carbons, heteroaryl, F, Cl, Br, I, CN, NO₂, OH, OR⁹, O(CH₂)_(n)NR⁷ R⁸, OCOR⁹, OCONHR⁹, O-tetrahydropyranyl, NH₂, NR⁷ R⁸, NR¹⁰ COR⁹ ;NR¹⁰ CO₂ R⁹, NR¹⁰ CONR⁷ R⁸, NHC(═NH)NH₂, NR¹⁰ SO₂ R⁹ ; S(O)_(y) R¹¹,wherein R¹¹ is H, alkyl of 1-4 carbons, aryl of 6-10 carbons, orheteroaryl, and y is 1 or 2; SR¹¹, CO₂ R⁹, CONR⁷ R⁸, CHO, COR⁹, CH₂ OR⁷,CH₂ OR⁹, CH═NNR¹¹ R¹², CH═NOR¹¹, CH═NR⁹, CH═NNHCH(N═NH)NH₂ ; SO₂ NR¹²R¹³, wherein either(1a) R¹² and R¹³, independently, are H, alkyl of 1-4carbons, aryl of 6-10 carbons, or heteroaryl; or (2a) R¹² and R¹³ arecombined together to form a --(CH₂)₂ --X¹ --(CH₂)₂ linking group;PO(OR¹¹)₂, NHR¹⁴, NR¹⁰ R¹⁴, OR¹⁴, and a monosaccharide of 5-7 carbonswherein each hydroxyl group of said monosaccharide is independentlyselected from the group consisting of unsubstituted hydroxyl and areplacement moiety replacing said hydroxyl group selected from the groupconsisting of H, alkyl of 1-4 carbons, alkylcarbonyloxy of 2-5 carbons,and alkoxy of 1-4 carbons; c) each R³ and R⁴, independently, is selectedfrom the group consisting of H, aryl of 6-10 carbons, heteroaryl, F, Cl,Br, I, CN, CF₃, NO₂, OH, OR⁹, O(CH₂)_(n) NR⁷ R⁸, OCOR⁹, OCONHR⁹, NH₂,(CH₂)_(n) OR⁹, (CH₂)_(n) OR¹⁰, (CH₂)_(n) OR¹⁴, OR¹⁴, NHR¹⁴, NR⁷ R⁸, NR⁷(CH₂)_(n) NR⁷ R⁸, NR¹⁰ COR⁹, NR¹⁰ CONR⁷ R⁸, SR¹¹, S(O)_(y) R¹¹, CO₂ R⁹,COR⁹, CONR⁷ R⁸, CHO, CH═NOR¹¹, CH═NR⁹, CH═NNR¹¹ R¹², (CH₂)_(n) SR⁹,(CH₂)_(n) S(O)_(y) R⁹ ; CH₂ SR¹⁵, where R¹⁵ is alkyl of 1-4 carbons; CH₂S(O)_(y) R¹⁴, (CH₂)_(n) NR⁷ R⁸, (CH₂)_(n) NHR¹⁴, alkyl of 1-8 carbons,alkenyl of 1-8 carbons, and alkynyl of 1-8 carbons; and either1) eachalkyl of 1-8 carbons, alkenyl of 1-8 carbons or alkynyl of 1-8 carbonsis unsubstituted; or 2) each alkyl of 1-8 carbons, alkenyl of 1-8carbons, or alkynyl of 1-8 carbons is independently substituted asdescribed in b)2) above; d) R⁵ is selected from the group consisting ofH, alkyl of 1-8 carbons, alkenyl of 1-8 carbons, and alkynyl of 1-8carbons; and either1) each alkyl, alkenyl, or alkenyl group isunsubstituted; or 2) each alkyl, alkenyl, or alkynyl group issubstituted with 1-3 groups selected from the group consisting of F, Cl,Br, I, CN, CF₃, NO₂, OH, OR⁹, O(CH₂)_(n) NR⁷ R⁸, OCOR⁹, OCONHR⁹, NH₂,(CH₂)_(n) OR⁹, (CH₂)_(n) OR¹⁴, NR⁷ R⁸, NR⁷ (CH₂)_(n) NR⁷ R⁸, NR¹⁰ COR⁹,NR¹⁰ CONR⁷ R⁸, SR¹¹, S(O)_(y) R¹¹, CO₂ R⁹, COR⁹, CONR⁷ R⁸, CHO,CH═NOR¹¹, CH═NR⁹, CH═NNR¹¹ R¹², (CH₂)_(n) SR⁹, (CH₂)_(n) S(O)_(y) R⁹,CH₂ SR¹⁵, CH₂ S(O)_(y) R¹⁴, (CH₂)_(n) NR⁷ R⁸, and (CH₂)_(n) NHR¹⁴ ; e) Xis selected from the group consisting of --N--, --O--, --S--, --S(═O)--,--S(═O)₂ --, alkylene of 1-3 carbons, --C(═O)--, --C(R²)═C(R²)--,--(CR²)₂ --, --CH═CH--, --CH(OH)--CH(OH)--, --C(═NOR¹¹)--,--C(OR¹¹)(R¹¹)--, --C(═O)CH(R¹⁵)--, --CH(R¹⁵)C(═O)--; --CH₂ --Z--,--Z--CH₂ --, --CH₂ ZCH₂ --, where Z is selected from the groupconsisting of --C(OR¹¹)(R¹¹)--, O, S, C(═O), and NR¹¹ ; and alkylene of1-3 carbons substituted with a group selected from the group consistingof one R⁵ substituent group, SR¹⁰, OR¹⁰, OR¹⁴, R¹⁵, phenyl, naphthyl,and arylalkyl of 7-14 carbons.
 2. The compound of claim 1 wherein R⁹ isselected from the group consisting of alkyl of 1-4 carbons, phenyl, andnaphthyl.
 3. The compound of claim 1 wherein R¹¹, R¹², and R¹³ are eachindependently selected from the group consisting of H, alkyl of 1-4carbons, phenyl, naphthyl, and heteroaryl.
 4. The compound of claim 1wherein R¹ is selected from the group consisting of H, alkyl of 1-4carbons, substituted phenyl, unsubstituted phenyl, OR¹⁰, and O(CH₂)_(n)R⁷ R⁸.
 5. The compound of claim 1 wherein R² is selected from the groupconsisting of H, C(═O)R⁹, alkyl of 1-8 carbons, and alkyl of 1-8 carbonssubstituted with one group selected from the group consisting of OR⁹,OH, OCOR⁹, NR⁷ R⁸, NH₂, NR¹⁰ COR⁹, and NR¹⁰ R¹⁴.
 6. The compound ofclaim 1 wherein R³ and R⁴ are each independently selected from the groupconsisting of H, F, Cl, Br, I, CN, OH, OR⁹, OR¹⁴, NH₂, NR⁷ R⁸, (CH₂)_(n)OR¹⁰, (CH₂)_(n) OR¹⁴, COR⁹, NR¹⁰ COR⁹, NHR¹⁴, and O(CH₂)_(n) NR⁷ R⁸. 7.The compound of claim 1 wherein R⁵ is selected from the group consistingof H and alkyl of 1-4 carbons.
 8. The compound of claim 1 wherein X isselected from the group consisting of --N--, --O--, --S--, alkylene of1-3 carbons, --C═O--, --CH₂ --Z--, and --Z--CH₂ --.
 9. The compound ofclaim 8 wherein X is selected from the group consisting of --N--, --O--,--S--, and --CH₂ --.
 10. The compound of claim 9 wherein R¹, R², R³, R⁴,and R⁵ are each H.
 11. The compound of claim 1 represented by Formula I.12. The compound of claim 11 wherein R¹ is selected from the groupconsisting of H, alkyl of 1-4 carbons, substituted phenyl, unsubstituedphenyl, OR¹⁰, and O(CH₂)_(n) R⁷ R⁸.
 13. The compound of claim 11 whereinR² is selected from the group consisting of H, C(═O)R⁹, alkyl of 1-8carbons, and alkyl of 1-8 carbons substituted with one group selectedfrom the group consisting of OR⁹, OH, OCOR⁹, NR⁷ R⁸, NH₂, NR¹⁰ COR⁹, andNR¹⁰ R¹⁴.
 14. The compound of claim 11 wherein R³ and R⁴ are eachindependently selected from the group consisting of H, F, Cl, Br, I, CN,OH, OR⁹, OR¹⁴, NH₂, NR⁷ R⁸, (CH₂)_(n) OR¹⁰, (CH₂)_(n) OR¹⁴, COR⁹, NR¹⁰COR⁹, NHR¹⁴, and O(CH₂)_(n) NR⁷ R⁸.
 15. The compound of claim 11 whereinR⁵ is selected from the group consisting of H and alkyl of 1-4 carbons.16. The compound of claim 11 wherein X is selected from the groupconsisting of --N--, --O--, --S--, alkylene of 1-3 carbons, --C═O--,--CH₂ --Z--, and --Z--CH₂ --.